{"id":"CVE-2026-93475","title":"Out-of-bounds Write via an Unbounded RSA Modulus in NetX Secure X.509","summary":"The X.509 parser in NetX Secure accepts an RSA public key of any size, but every signature-verification path decrypts into fixed-size buffers dimensioned for the `NX_CRYPTO_MAX_RSA_MODULUS_SIZE` default of 4096 bits. A certificate carryi…","severity":"critical","cvss":9.3,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","cvssSource":"cna","cwe":["CWE-787","CWE-1284"],"vendor":"Eclipse Foundation","product":"NetX Duo","affected":["netx_duo <= 6.5.1.202602"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-20T17:02:43.642743Z"},"published":"2026-10-20","updated":"2026-10-20","sourceUpdated":"2026-10-20T17:02:52.372Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-93475","references":[{"url":"https://github.com/eclipse-threadx/netxduo/security/advisories/GHSA-rcv5-vfff-25gh"}],"tags":["cve.org"],"ingestedAt":"2026-10-20T16:10:53.334Z","slug":"CVE-2026-93475","body":"## Overview\n\nThe X.509 parser in NetX Secure accepts an RSA public key of any size, but every signature-verification path decrypts into fixed-size buffers dimensioned for the `NX_CRYPTO_MAX_RSA_MODULUS_SIZE` default of 4096 bits. A certificate carrying a larger modulus drives an out-of-bounds write past a file-scope static during ordinary certificate-chain verification.\n\n\n\nIt is reachable pre-authentication. The issuer used for the crypto operation is looked up in the remote, peer-supplied store before the trusted store, so the attacker supplies the oversized key themselves as an intermediate in the chain they present. It triggers on a TLS or DTLS client verifying a malicious server's chain, and on a server performing client-certificate authentication.\n\n## Affected\n\n- `netx_duo <= 6.5.1.202602`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":51,"depthScoreParts":{"impact":51.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}